• The dissension and war between the Emperor Frederick the Second and Pope Gregory the Ninth. Milman, History of Latin Christianity , Book X Ch. 3, says:⁠— “The Empire and the Papacy were now to meet in their last mortal and implacable strife; the two first acts of this tremendous drama, separated by an interval of many years, were to be developed during the pontificate of a prelate who ascended the throne of St. Peter at the age of eighty. Nor was this strife for any specific point in dispute, like the right of investiture, but avowedly for supremacy on one side, which hardly deigned to call itself independence; for independence, on the other, which remotely at least aspired after supremacy. Caesar would bear no superior, the successor of St. Peter no equal. The contest could not have begun under men more strongly contrasted, or more determinedly oppugnant in character, than Gregory the Ninth and Frederick the Second. Gregory retained the ambition, the vigor, almost the activity of youth, with the stubborn obstinacy, and something of the irritable petulance, of old age.